In general, a pneumatic tire, in particular, a pneumatic tire for a motorcycle is known to be largely affected, in terms of drivability, by the shape of grooves (tread pattern) formed in a tread surface of a tread portion.
As an example of a conventional pneumatic tire for a motorcycle, there has been proposed a pneumatic tire for a motorcycle having a circumferential groove extending substantially in the tire circumferential direction and a plurality of lateral grooves extending substantially in the tire width direction, the grooves being formed in a tread surface of the tire (see, for example, Patent Literatures 1, 2). In the aforementioned pneumatic tire for a motorcycle, the circumferential groove functions to improve drivability and to prevent skidding while the lateral grooves exert drive force and braking force.
However, the grooves formed in a tread surface of the tread portion, which may improve the drivability or the like, also reduces the rigidity of the tread portion to generate a difference in rigidity. As a result, a pneumatic tire for a motorcycle having a circumferential groove and a lateral groove formed in a tread surface of a tread portion for the purpose of ensuring drivability can be subjected to significant partial wear, and thus it has been difficult to ensure both drivability and partial wear resistance at the same time.